Polyurethane foams have been used to form seals and gaskets in a variety of industries, such as the automotive industry, the appliance industry, the aerospace industry, and the electronics industry. Polyurethane foams can be used to form gaskets through various techniques such as foam-in-place methods, molded methods, or transfer molding methods. Further, polyurethanes can be used in a variety of densities ranging from high densities to low densities.
In particular, polyurethane may be formed using a two component system or a one component system. In a conventional two component system, a polyol component and a diisocyanate component are mixed immediately prior to use. As such, two component systems have disadvantages including difficulties associated with strict control of stoichiometric mixing of the components and difficulties associated with clearing lines and cleaning equipment to prevent cure of the polyurethane within a dispensing system.
Alternatively, one component polyurethane systems can be used, which are conventionally cured in the presence of water. One component polyurethane components can be mixed with water prior to dispensing or can be moisture cured after dispensing. Moisture cured one component polyurethane foams conventionally rely on high humidity boxes to facilitate curing. Such high humidity boxes occupy a significant amount of space within a factory producing large numbers of components. In addition, such high humidity boxes utilize a significant amount of energy to both maintain a high temperature within the box, as well as to maintain a high humidity within the box by evaporating moisture. In times of increased concern over the environmental impact of energy production, the significant energy usage of high humidity boxes has a negative impact on the environmental impact of a manufacturing facility. In addition, high humidity box equipment represents a significant investment cost.
As such, an improved polyurethane gasket and method of forming such a gasket would be desirable.
The use of the same reference symbols in different drawings indicates similar or identical items.